新疆阿尔泰阿舍勒矿集区铜多金属矿床模型

摘要

Ashele is a very important polymetallic copper ore-concentrated area in Xinjiang, and the ore are hosted in the volcanic rocks of the Lower-Middle Devonian Ashele Formation. The area hosts diverse types of mineralization and complex combinations of ore-forming elements (Cu, Cu-Zn, Cu-Zn-Au, Cu-Pb-Zn-Au, Cu-Pb-Zn-Ag). The Ashele Formation formed during 402~375 Ma, and the associated mineralization lasted for 15 Ma in the interval of 394~379 Ma. Systematic study of the Ashele copper-zinc deposit and the Sarsuk polymetallic gold deposit, and combined with a detailed study of the data available, the authors put forward a metallogenetic model for the Ashele ore-concentrated area. Despite the diverse types of mineralization and complex combinations of ore metals, the ore-forming processes were closely associated with the volcanism as a unified VMS mineralization system, only different in occurrences. The layered copper-zinc orebodies and barite orebodies were formed by exhalative sedimentation in the volcanic slopes and depressions, the veinlet copper (zinc) orebodies and copper-zinc-lead orebodies were formed in the stringer or stockwork zone, veinlet gold-copper-lead-zinc ores were formed during the intrusion of the rhyolite porphyry. The copper ores ere formed in the dacite porphyry, subvolcanic contact zones, as well as fault or fracture.%阿舍勒是新疆十分重要的铜多金属矿集区,矿化均赋存于下–中泥盆统阿舍勒组火山岩系中。矿化类型多,成矿元素组合复杂(Cu、Cu-Zn、Cu-Zn-Au、Cu-Pb-Zn-Au、Cu-Pb-Zn-Ag)。阿舍勒组火山活动时间是402~375 Ma,矿化时间为394~379 Ma,持续了15 Ma。本文通过对阿舍勒铜锌矿和萨尔朔克金多金属矿的系统研究,提出阿舍勒矿集区矿床模型,认为尽管矿集区铜多金属矿化类型多,成矿元素组合复杂,但成矿均与火山作用有关,属同一 VMS 成矿系统,只是不同部位存在矿化差异。在火山斜坡和洼地喷流沉积形成层状铜锌矿体和重晶石矿体,补给通道中形成脉状铜(锌)矿体和铜铅锌银矿体,潜流纹岩中形成脉状金铜铅锌矿体,潜英安岩中形成铜矿体,潜火山岩接触带形成铜矿体,在断裂或裂隙中形成铜矿体。